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Drupal PECL YAML parser unsafe object handling

Critical severity GitHub Reviewed Published May 14, 2022 to the GitHub Advisory Database • Updated Apr 23, 2024

Package

composer drupal/core (Composer)

Affected versions

>= 8.0, < 8.3.4

Patched versions

8.3.4
composer drupal/drupal (Composer)
>= 8.0, < 8.3.4
8.3.4

Description

Drupal core 8 before versions 8.3.4 allows remote attackers to execute arbitrary code due to the PECL YAML parser not handling PHP objects safely during certain operations.

References

Published by the National Vulnerability Database Aug 6, 2018
Published to the GitHub Advisory Database May 14, 2022
Reviewed Apr 23, 2024
Last updated Apr 23, 2024

Severity

Critical

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS score

6.571%
(94th percentile)

Weaknesses

CVE ID

CVE-2017-6920

GHSA ID

GHSA-9c24-g32g-35rj

Source code

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